Method and apparatus for applying color coded striping to miniature components



ec. 13, 1956 A. RAMOS 3,291,637

METHOD AND APPARATUS FOR APPLYING COLOR CODED STRIPING TO MINIATURECOMPONENTS Filed June 1, 1964 2 heets-sheet 1 ji a 3 t 1 Q\ Q 0 i N L! 3Q INVENTOR. 44 70/100 Q4/1105 Dec. 13, 1966 RAMOS 3391,63?

METHOD AND APPA US APPLYING COLOR CODED STRIPING MINIATURE COMPONENTSFiled June 1, 1964 2 Sheets-Sheet 2 .95 IN V EN TOR. 4/1 70/1/0 2/4/1405United States Patent METHOD AND APPARATUS FOR APPLYING COLOR CODEDSTRIPING T0 MINIATURE COMPONENTS Antonio Ramos, Cumberland, R.I.,assignor to General Instrument Corporation, Newark, N..I., a corporationof New Jersey Filed June 1, 1964, Ser. No. 371,635 20 Claims. (Cl.117-212) This invention relates to the marking or color coding ofelectronic components, and more particularly to a machine for markingmicrodiodes.

Electronic components are becoming smaller, and have gone from miniatureto microminiature. The invention as here illustrated is applied to themarking of a microdiode which has an insulation body only one-tenth inchlong, with oppositely projecting lead Wires one-half inch long.Components are marked by standardized color code stripes, and in thepresent case the stripes are to be spaced only twenty-five thousandthsof an inch from center to center.

One method of color marking is by hand. A more usual machine method isby indirect transfer of the marking from color print wheels or discsthrough a rubber surfaced transfer wheel to the component being marked,but this and other methods present great difficulty when making the verynarrow and closely spaced stripes here required. It is important to keepthe stripes accurate and distinct, and to prevent contact and bleedingbetween stripes.

The general object of the present invention is to overcome the foregoingdifliculties, and to provide a marking machine for tiny components,particularly of microminiature size. In accordance with the presentinvention a plurality of thin filaments or wires are first coated, andthese are guided very close to one another in collateral relation, andare simultaneously moved laterally into contact with the component to bemarked.

Further objects of the invention are to control the thickness of thecoating on the wire; to eliminate the coating on one side of the wirewhere it is not used; and to advance the wire a small amount to presenta new segment of coated wire for each marking operation.

Another requirement is that the marking be applied to a specified leadof the component. In the case of a diode the marking is to be applied tothe cathode lead, it being understood that we deal here with a componentthe body of which is too small to receive the marking, or is so shapedthat it would be difiicult to apply the marking. In accordance withanother feature and object of the present invention the polarity of thediode is checked as it is placed in the marking machine, so that ifwrong it may be reversed to properly polarize the same.

To accomplish the foregoing general objects, and other more specificobjects which will hereinafter appear, my invention resides in themarking machine elements, and their relation one to another, as arehereinafter more particularly described in the following specification.The specification is accompanied by drawings in which:

FIG. 1 is a plan view of a marking machine embodying features of theinvention;

FIG. 2 is an elevation thereof;

FIG. 3 is a perspective view showing a pedestal on which the componentis placed for marking;

FIG. 4 is a fragmentary section showing one of the ink containers forcoating a wire;

FIG. 5 is a fragmentary view taken on the line 5-5 of FIG. 4;

FIG. 6 is a section through a coated wire;

FIG. 7 is a fragmentary section through the wires at the printingstation; and

Patented Dec. 13, 1966 FIG. 8 is an electrical diagram for the polaritychecking circuit.

Referring to the drawing, and more particularly to FIG. 3, the componentis a microminature diode sealed in a plastic housing 12, with oppositelyprojecting lead wires 14 and 16 having a length of say one-half inch.One lead Wire, in this case the cathode lead 14, is to receive the colorcoded stripes, and in the present case there are five such stripeshaving a spacing of twentyfive thousandths of an inch, with clearancebetween stripes of ten thousandths inch.

Referring now to FIG. 2 of the drawing, the apparatus comprises means at20 to coat a plurality of thin filaments or wires with appropriatecolors, there being one filament for each stripe. There is an additionalmeans, in this case a grooved spacer wheel 22, to guide the coatedfilaments very close to one another in collateral relation. There isalso a means, in this case a manually operable handle 24, tosimultaneously move all of the coated filaments laterally into contactwith and then away from an electronic component at a marking station 26.The wheel 22 is here shown in down position. There is also a means,generally designated 30, to move all of the filaments simultaneouslylengthwise a small amount to present new segments of the coatedfilaments. Thus, the filaments are cyclically moved longitudinally andlaterally into contact with successive electronic components placed atstation 26.

Considering the machine in greater detail, and referring to FIGS. 1 and2, there is a pedestal 32 to support a component, with one lead wireexposed to receive the marking. An upright movable mounting plate 34carries a plurality of reels 36 of thin wire, one for each stripe. Inthe present case there are five reels for five stripes. If small, thereels may be mounted directly on plate 34, but to avoid winding specialsmall reels, in the present case larger commercially available reels areemployed, and are mounted on an arm 38 fixedly secured to andeffectively forming a part of the plate 34. Because the commercial reelshave appreciable width, as seen in FIG. 1, the arm 38 may be displacedsidewardly from plate 34, as by means of a block 40.

The plate 34 also carries a plurality of ink containers shown at 20 inFIG. 2, and each of these containers terminates in a long thin tube 42,preferably having an inside diameter only a few thousandths of an inchgreater than the diameter of the wire. These tubes 42 run at diflerentangles to points preferably closely approaching the grooved spacer Wheel22 previously mentioned.

The plate 34 also carries guide means to guide the wires from the reels36 through the containers 20 and tubes 42. In the present case there areeyes 44 carried by a bar 46 projecting from the arm 38, followed bysheaves 48 which are coaxial, and which are followed by spaced sheaves50, one for each wire and ink container. This arrangement is employed inorder to bring the wires close together. The eyes 44 represent a firststage of convergence, and the coaxial sheaves provide a second stage ofconvergence. However, at sheaves/38 the minimum spacing is limited bythe sheaves themselves, and accordingly the sheaves 50 are on separatespaced axes, so that they may overlap in axial direction, thereby makingit possible to bring the wires to as close a spacing as is desired. Thisspacing may approach or even equal the final spacing, say twentyfivethousandths of an inch.

The base 52 of the machine carries fixed bearings 54 and 56 (FIG. 1)which carry a plurality of taken-p reels or spools 58. These are smallin axial direction, and are secured to a common shaft 68, which shaftalso carrries a ratchet wheel 60. Plate 34 may be provided with a pawl62 engaging the ratchet wheel 60 as later described. There is a frictionbrake at 61.

FIG. 2 shows plate 34 in its down position. It is normally urged upwardby resilient means, in this case a compression spring 64. The upwardmotion is limited to a. suitable amount, say one-half inch, at thepedestal 32, which is adequate for loading and unloading the pedestal.Handle 24 is fixed directly on plate 34, and serves as a manual means tomove the plate downward. However, a treadle may be provided for footoperation, in which case a suitable cord or chain 66 may extend downwardto the treadle.

The takeup spools 58 are advanced slightly for each printing movement ofthe plate, and to facilitate this the plate 34 is preferably pivoted onthe axis of ratchet wheel 60, that is, on shaft 68 between bearings 54and 56. 'The pawl 62 is preferably faced as shown, so that it moves theratchet wheel during upward movement of plate 34, but it could be facedthe other way.

Referring now to FIG. 5, the ink container 20 may be tapered at itslower end 70 leading to the long slender tube 42. This tube has aninside diameter slightly greater than the diameter of the wire 72. Thetube is preferably so oriented that the wire rubs against one side ofthe tube at the discharge end of the tube, as shown at 74. This is theside of the wire which engages the spacer wheel. Thus, in FIG. 2 all ofthe tubes 42 are displaced very slightly to the left at their lowerends, in which case the wires are wiped clean on the side engagingspacer wheel 22, and carry ink on the outer sides which come intocontact with the component to be marked. This is also shown in FIG. 6,in which wire 72 is coated heavily on the bottom as shown at 76, but isuncoated on topwhere it engages the grooved spacer wheel 22.

To facilitate adjustment of the inking tubes, each container and tubemay be angularly adjustable in the plane of the path of the wire asshown in FIG. 2, or differently expressed, in a plane perpendicular tothe axis of the spacer wheel 22. The ink containers are received betweenspaced strips or holders 120 and 121 shown in FIG. 4. These may be heldtogether and on the plate 34 (FIG. 2) by screws 122. The bottom isclosed except for a longitudinal slit 123 through which the tubes 42pass. The angular position of each container may be locked, as by meansof a set screw 124. It will be evident that with this arrangement thetube may be positioned with its lower end toward the left, as Viewed inFIG. 2, relative to its wire, thereby accomplishing the desired Wipingaction shown at the bottom of FIG. 5.

The adjustment of the tubes axially of the spacer wheel 22 may beaccomplished at the same time, as by the insertion of shims on one sideor the other, and in any event is not critical because the very slightdisplacement needed at the lower end of the tube may be accomplished bythe wire itself, as guided or fixed by the receptive groove of thespacer wheel 22. The shims which may be used are not shown in thedrawing.

A convenient way to provide the ink container 20 is to employ thecombined body and needle of a conventional hypodermic syringe, theneedle size being properly selected for the desired coating thickness.case shown, the wire has a diameter of thirteen thousanths inch, and theinside diameter of the tube 42 is sixteen thousandths inch, thusproviding a coating at 76 (FIG. 6) of three thousandths inch.

The purposes of the slender tube 42 are to limit the amount of fluid todesired thickness, and to remove the fluid from that side of the wirewhich will not come in contact with the part to be marked. By itscapillary nature it also prevents unwanted dripping of the fluid fromthe lower end of the tube.

Referring now to FIG. 3, the pedestal 32 has a pocket at 80 large enoughto receive the body 12 of the microdiode. There is a groove at 82 toreceive the lead 16, and a groove at 84 to receive the lead 14, but thepedestal is cut away at 86 to expose part of the lead 14 to the coatedwires. This construction is also shown in FIG. .7, the

In the particular body 12 being received in pocket 80, the lead 16 ingroove 82, the outer end of lead 14 in groove 84, while theinner portionof lead 14 rests on the pedestal, but is exposed to the wires carried byspacer wheel 22.

The marking is to be applied to the cathode lead, and it is thereforenecessary to properly polarize the microdiode when placing it on thepedestal. The polarity test may be made in advance, but it is safer andmore convenient to check the polarity at the pedestal. For this purposethe pedestal is made of two conductive parts 88 and 90 (FIG. 3)separated by insulating material 92. It is convenient to form the recessin the insulating material 92, which therefore is given a thicknesscorresponding to the length of the body 12 of the microdiode. The parts88 and 90 have lead wires 94 and 95 extending therefrom, and the entirepedestal may be mounted on insulating material indicated at 96.

The circuit for checking polarity may be exceedingly simple, andreferring to FIG. 8, a battery 98, or any other convenient D.C. source,is connected in series with the pedestal 88 and 90, and in series with alamp or other desired indicator. When the diode is properly polarized ittransmits current, and the lamp lights. When the diode is improperlypolarized the lamp does not light, and the operator is thereby warned toreverse the diode before marking it.

Reverting to FIG. 2, the eyes 44 are preferably yieldably mounted. Inthe present case each eye is carried on an upright shank which isvertically slidable in bar 46. The shank carries a light compressionspring 102, permitting the eye to move upward in the event of unduetension on the wire.

To keep the wires individually and independently taut, the reels 36preferably are not secured together, and each is provided with its ownfriction braking means. In the present case the brake comprises a shoe104 carried at one end of leaf spring 106. The springs 106 are securedto blocks 108, which are carried on a spindle 110 and have set screws 112.

The wires leading to the takeup spools 58 are preferably cleaned, andfor this purpose a cleaning device is shown at 114 (FIG. 2). This is asmall metal container which is open at the top, and which is filled witha felt or other absorbent body which is wetted from time to time by theaddition of a solvent or cleaning fluid.

The used wire may be rewound and reused, and in such case small supplyreels may be mounted at about the location of the sheaves 48, andprovided with a crank for rewinding the same. However, the very thinwire used is so inexpensive that it is found more economical to discardthe wire after it has been used. It is therefore not essential to cleanthe wire on its way to the takeup spools 58, but the cleaning device isconvenient because it makes the task of removing and replacing thetakeup spools 58 less messy.

The paint or color is a marking ink which :air dries and later is baked.In practice the marked diodes are placed on a tray, and the tray ismoved to a baking oven.

It is believed that the construction and method of use of my improvedmarking machine, as well as the advantages thereof, will be apparentfrom the foregoing detailed description. The multiple color stripes areapplied to close tolerance, with uniformity, and good quality. Thestripes are distinctly separated, with no bleeding therebetween. Themark is applied with proper polarization. The operation may be performedrapidly, despite the minute size of the stripes to be applied, and ifneeded, the machine could apply even smaller stripes at smaller spacingthan here mentioned as a specific example, until so small that the nakedeye is no longer able to distinguish the colors.

It will be apparent that while I have shown and described the markingmachine in a preferred form, changes may be made in the structure shown,Without departing '5 from the scope of the invention as sought to bedefined in the following claims.

I claim:

1. The method of applying color coded stripes to miniature componentswhich includes first coating a plurality of thin filaments withappropriate color, there being one filament for each stripe of the colorcode, guiding the coated filaments very close to one another incollateral relation, and simultaneously moving all of the coatedfilaments laterally into contact with and then away from a componentwhich is to be color coded.

2. The method of applying color coded stripes to miniature electroniccomponents which includes first coating a plurality of thin filamentswith appropriate color, there being one filament for each stripe of thecolor code, guiding the coated filaments very close to one another incollateral relation, simultaneously moving all of the coated filamentslaterally into contact with and then away from an electronic componentwhich is to be color coded, moving all of the filaments simultaneouslylengthwise a small amount to present new segments of the color coatedfilaments, again moving all of the filaments laterally into contact withanother electronic component to be color coded, and so on.

3. Apparatus for applying color coded stripes to miniature components,said apparatus comprising means to coat a plurality of thin filamentswith appropriate color, there being one filament for each stripe of thecolor code, means to guide the coated filaments very close to oneanother in collateral relation, and means to simultaneously move all ofthe coated filaments laterally into contact with and then away from acomponent which is to be color coded.

4. Apparatus for applying color coded stripes to miniature electroniccomponents, said apparatus comprising means to coat a plurality of thinfilaments with appropriate color, there being one filament for eachstripe of the color code, means to guide the coated filaments very closeto one another in collateral relation, means to simultaneously move allof the coated filaments laterally into contact with and then away froman electronic component which is to be color coded, and means to moveall of the filaments simultaneously lengthwise a small amount to presentnew segments of the color coated filaments, whereby the filaments may becyclically moved longitudinally and laterally into contact withsuccessive electronic components to be color coded.

5. Apparatus for applying color coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support and expose acomponent to receive the color code marking, a mounting plate carrying aplurality of reels of thin wire, one for each stripe, a plurality of inkcontainers each terminating at the bottom in a long thin tube having aninside diameter slightly greater than the diameter of the wire, a spacerhaving shallow grooves at the desired spacing of the stripes, guidemeans to guide the wires from the reels through the containers and tubesto the spacer, a plurality of takeup spools for receiving the wiresleaving the spacer, said pedestal and mounting plate being relativelymovable to bring the coated spaced wires against the component, andmeans to advance the takeup spools slightly for each printing movementof the plate and pedestal.

6. Apparatus as defined in claim 5, in which the ink containers andtubes are angularly adjustable in the plane of the path of the wire, andare so adjusted that the tube ends bears against and leaves uncoatedthat side of the wire which engages the spacer.

7. Apparatus as defined in claim 5, which the pedestal has twoconductive sides insulated from one another, one side receiving one leadwire and the other side receiving the other lead wire of the component,and in which there are electrical connections from said pedestal sidesto a polarity testing circuit, whereby the operator may check thepolarity of the component before marking the same.

8. Apparatus as defined in claim 5, in which each container and tube isthe body and needle of a hypodermic syringe.

9. Apparatus for applying color coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support and expose acomponent with a lead wire to receive the color code marking, a mountingplate carrying a plurality of reels of thin wire, one for each stripe, aplurality of ink containers each terminating at the bottom in a longthin tube having an inside diameter slightly greater than the diameterof the wire, a spacer having shallow grooves at the desired spacing ofthe stripes, guide means to guide the wires from the reels through thecontainers and tubes to the spacer, a plurality of takeup spools forreceiving the wires leaving the spacer, said pedestal and mounting platebeing relatively movable to bring the coated spaced wires against thelead wire of the component, resilient means urging the pedestal andplate apart, manual means to move them toward one another, and means toadvance the takeup spools slightly for each printing movement of theplate and pedestal, said means including a ratchet Wheel for turning thespools and a pawl engaging the ratchet wheel.

10. Apparatus for applying color coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support a componentwitha lead wire exposed to receive the color code marking, a mountingplate carrying a plurality of reels of thin wire, one for each stripe, aplurality of ink containers each terminating at the bottom in a longthin tube having an inside diameter slightly greater than the diameterof the wire, a spacer wheel having shallow grooves at the desiredspacing of the stripes, guide means to guide the wires from the reelsthrough the containers and tubes to the spacer wheel, a plurality oftakeup spools for receiving the wires leaving the spacer wheel, saidpedestal and mounting plate being relatively movable to bring the coatedspaced Wires at the spacer wheel against the lead wire of the component,and means to advance the takeup spools slightly for each printingmovement of the plate and pedestal.

11. Apparatus as defined in claim 10, in which the ink containers andtubes are angularly adjustable in a plane perpendicular to the axis ofthe spacer wheel, and are so adjusted that the tube end bears againstand leaves uncoated that side of the wire which engages the spacerwheel.

12. Apparatus as defined in claim 10, in which the pedestal has twoconductive sides insulated from one another, one side receiving one leadwire and the other side receiving the other lead Wire of the component,and in which there are electrical connections from said pedestal sidesto a polarity testing circuit, whereby the operator may check thepolarity of the component before marking the same.

13. Apparatus for applying color coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support a componentwith a lead wire exposed to receive the color code marking, a mountingplate carrying a plurality of reels of thin wire, one for each stripe, aplurality of ink containers each terminating at the bottom in a longthin tube having an inside diameter slightly greater than the diameterof the wire, a spacer wheel having shallow grooves at the desiredspacing of the stripes, guide means to guide the wires from the reelsthrough the containers and tubes to the spacer wheel, a plurality oftakeup spools for receiving the wires leaving the spacer wheel, saidpedestal and mounting plate being relatively movable to bring the coatedspaced wires at the spacer wheel against the lead wire of the component,resilient means urging the pedestal and plate apart, manual means tomove them toward one another, and means to advance the takeup spoolsslightly for each printing movement of the plate and pedestal, saidmeans including a ratchet wheel for turning the spools and a pawlengaging the ratchet wheel.

14. Apparatus for applying color'coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support a componentwith a lead wire exposed to receive the color code marking, a mountingplate carrying a'plurality of reels of thin'wire, one for each stripe, aplurality of ink containers each terminating at the bottom in a longthin tube having an inside diameter slightly greater than the diameterof the wire, a spacer wheel having shallow grooves at the desiredspacing of the stripes, guide means to guidethe wires from the reelsthrough the containers and tubes to the spacer wheel, a plurality oftakeup spoolsfor receiving the wires leaving the spacer wheel, saidmounting plate being movable downward to bring the coated spaced wiresat the spacer wheel against the lead wire of the component, and means toadvance the takeup spools slightly for each printing movement of theplate. v

15. Apparatus as defined in claim 14, in which the ink containers andtubes are angularly adjustable in a plane perpendicular to the axis ofthe spacer wheel, and are so adjusted that the tube end bears againstand leaves uncoated that side of the wire which engages the spacerwheel.

16. Apparatus as defined in claim 14, in which the pedestal has twoconductive sides insulated from one another, one side receiving one leadwire and the other side receiving the other lead wire of the component,and inwhich there are electrical connections from said pedestal sides toa polarity testing circuit, whereby the operator may check the polarityof the component before marking the same. i

17 Apparatus for applying color coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support a componentwith a lead wire exposed to receive the color code marking, a mountingplate carrying a plurality of reels of thin wire, one for each stripe, aplurality of ink containers each terminating at the bottom in a longthin tube having an inside diameter slightly greater than the diameterof the wire, a spacer wheel having shallow grooves at the desiredspacing of the stripes, guide means to guide the wires from the reelsthrough the containers and tubes to the spacer wheel, a plurality oftakeup spools for receiving the wires leaving the spacer wheel, saidmounting plate being movable downward to bring the coated spaced Wiresat the spacer wheel against the lead'wire of the component, resilientmeans urging the plate upward, manual means to move the plate downward,and means to advance the takeup spools slightly for each printingmovement of the plate.

18. Apparatus for applyingcolor coded stripes to miniature electroniccomponents, said apparatus comprising a pedestal to support a componentwith a lead wire exposed to receive the color code marking, a mountingplate carrying a plurality of reels of thin wire, one for each stripe, aplurality of ink containers each terminating at the bottom in a longthin tube having an inside diameter slightly greater than'the diameterof the wire, a spacer Wheel having shallow grooves at the desiredspacing of the stripes, guide means to guide the wires from the reelsthrough the containers and tubes to the spacer wheel, a plurality oftakeup spools for receiving the Wires leaving the spacer wheel, saidmounting plate being movable downward to bring the coated spaced wiresat the spacer wheel against the lead wire of the component, resilientmeans urging the plate upward, manual means to move the plate downward,and means to advance the takeup spools slightly for each printingmovement of the plate, said means including a ratchet wheel for turningthe takeup spools and a pawl on the plate engaging the ratchet wheel andso faced as to move the ratchet wheel on upward movement of the plate,said plate being pivoted for movement on the axis of the spools andratchet wheel.

19. Apparatus as defined in claim 18, in which the ink containers andtubes are angularly adjustable in a plane perpendicular to the axis ofthe spacer wheel, and are so adjusted that the tube end bears againstand leaves uncoated that side of the wire which engages the spacerwheel.

20. Apparatus as defined in claim 18, in which the pedestal has twoconductive sides insulated from one another, one side receiving one leadwire and the other side receiving the other lead wire of the component,and in which there are electrical connections from said pedestal sidesto a polarity testing circuit, whereby the operator may check thepolarity of the component before marking the same.

No references cited.

RALPH S. KENDALL, Primary Examiner.

ALAN M. GRIMALDI, Assistant Examiner.

1. THE METHOD OF APPLYING COLOR CODED STRIPES TO MINIATURE COMPONENTSWHICH INCLUDES FIRST COATING A PLURALITY OF THIN FILAMENTS WITHAPPROPRIATE COLOR, THERE BEING ONE FILAMENT FOR EACH STRIPE OF THE COLORCODE, GUIDING THE COATED FILAMENTS VERY CLOSE TO ONE ANOTHER INCOLLATERAL RELATION, AND SIMULTANEOUSLY MOVING ALL OF THE COATEDFILAMENTS LATERALLY INTO CONTACT WITH AND THEN AWAY FROM A COMPONENTWHICH IS TO BE COLOR CODED.
 3. APPARATUS FOR APPLYING COLOR CODEDSTRIPES TO MINIATURE COMPONENTS, SAID APPARATUS COMPRISING MEANS TO COATA PLURAITY OF THIN FILAMENTS WITH APPROPRIATE COLO, THERE BEING ONEFILAMENT FOR EACH STRIPE OF THE COLOR CODE, MEANS TO GUIDE THE COATEDFILAMENTS VERY CLOSE TO ONE ANOTHER IN COLLATERAL RELATION, AND MEANS TOSIMULTANEOUSLY MOVE ALL OF THE COATED FILAMENTS LATERALLY INTO CONTACTWITH AND THEN AWAY FROM A COMPONENT WHICH IS TO BE COLOR CODED.